I was planning on releasing everything Iíve learned at a later date but due to some mud-slinging Iím being forced to do this sooner rather than later. Please take this as you would anything else. It is not a secret that after this testing I decided to try and make a better nozzle, especially for higher horsepower applications. Some of you will probably argue that Iím biased or perhaps even made this up and thatís up to you. Anyone who knows what Bosio vs. Bosch nozzles cost plus paying for machine work will see that Iím not in this to get rich.
To give you guys a little background- Iíve been into diesels since 2002. Iíve owned 3 Duramaxes and currently own two as well as 2 A4 Jetta TDIís. Iíve been into competition since 2003 and currently have one Duramax with a fully-built race motor that is basically dedicated to drag racing and sled pulling. My other Duramax is a dually which I use to tow the race truck around. Iíve had a lot of experience with different diesel performance parts- turbos, injectors, cams, heads, studs, transmissions, etc. Iíve broken quite a few things during the development of many of the parts that are sold today for the Duramax. Iíve even manufactured a couple different things and still sell a few products for the Duramax. Up until last year I owned and operated dieselplace.com
, the largest Chevrolet & GMC diesel truck forum in the world.
If you would like to know more about my truck and what Iíve accomplished with it please see:
When I bought my TDIís my goal was to find the best parts I could for my two cars. If I found something I didnít like my plan was to utilize my experience and industry connections to improve upon what is currently available. Last year I decided I wanted to put bigger nozzles in my cars. I looked at what was readily available and found Bosch, Bosio, and some Chinese nozzles sold on eBay. I also found DSS nozzles but they didnít seem to be readily available over here so I didnít include them in my testing. Based on what I had read on the club (which Iím sure comes to no surprise) it seemed that Bosio was by far the most popular choice. I procured the following different nozzles, each set being brand new in the original packaging (I even tested several sets of the same type of certain models):
Bosio Sprint 520
Bosio Race 520 5-hole
Bosio Race 520 7-hole
Chinese eBay nozzles
Here is a picture of one of the Bosio boxes I received. They all looked identical and had the same distributorís sticker on them. I hope this is the best way to assume they are all genuine. I also purchased them from several different vendors on the forum so they wouldnít come from just one source.
I then sent them off to have them tested. My initial hope was that they would say the Bosioís were superior and I would then pick the size I wanted and move on to my next project. However that was not what I found.
To give a little background of what type of testing I had performed- Each nozzle was internally inspected for surface finish (inside the nozzle, not outside), potential EDM manufacturing damage, spray pattern, and consistency of flow. To make this simple Iíll use a Bosch 706 nozzle as my baseline. We tested several sets of these nozzles and every one of them flow tested exactly the same. The spray patterns were perfect and there was no sign of manufacturing defects. Bosch EDMís their nozzles initially then briefly hones them to remove any small imperfections from the EDM process.
Bosch 706 nozzle pictured below:
The Chinese nozzle was not surprisingly the least-desirable of those tested. We found the holes were actually drilled and not EDMíd. There was no evidence of EDM damage as that process was not utilized. The spray pattern was not as uniform as the baseline nozzle but surprisingly not horrible either. The major downside was the variance in the flow from nozzle to nozzle. I only tested one set of these and they flowed 35.714%, 78.571%, 43.264%, and 61.119% over stock for a set average of 57.143% over stock. One of the big things that make a great truck nozzle is to have each of them flow as close together as possible so you get an even distribution of fuel for each cylinder. Itís easier on the motor, especially when you are trying to make a lot of horsepower.
All of the Bosio nozzles were EDMíd so I wonít cover that aspect for each one.
The PP357ís showed no internal manufacturing defects from the EDM process. The spray pattern was good as was the surface finish. They flowed 21.429%, 28.571%, 35.714%, and 42.857% over stock for a set average of 32.143% over stock.
Two of the 8 Sprint 520ís tested showed burn marks from the EDM wire over penetrating the hole and residual slag material from the EDM process. The spray pattern was good and other than the EDM damage the surface finish was fine. The first set flowed 28.571, 35.714, 42.857%, and 42.857% over stock for a set average of 37.5% over stock. The second set flowed 35.714, 39.286%, 41.429%, and 42.857% over stock for a set average of 39.821% over stock.
Bosio sprint 520 pictured below:
The PP520ís showed no internal manufacturing defects from the EDM process. The spray pattern was good as was the surface finish. The first set flowed 50%, 46.429%, 57.143%, and 57.143% over stock for a set average of 52.679% over stock. The second set flowed 50%, 46.429%, 53.571%, and 57.143% over stock for a set average of 51.786% over stock.
Bosio PP520 pictured in both photos below:
The PP502ís showed no internal manufacturing defects from the EDM process. The spray pattern was good as was the surface finish. They flowed 64.286%, 67.857%, 71.429%, and 71.429% over stock for a set average of 68.75% over stock.
The PP764ís showed no internal manufacturing defects from the EDM process. The spray pattern was good as was the surface finish. They flowed 92.857%, 89.286%, 85.714%, and 71.429% over stock for a set average of 84.821% over stock.
The Race520 5-hole nozzles showed no internal manufacturing defects from the EDM process. The spray pattern was good as was the surface finish. They flowed 128.571%, 125%, 135.714%, and 128.571% over stock for a set average of 129.464% over stock.
The Race520 7-hole nozzles showed no internal manufacturing defects from the EDM process. The spray pattern was poor in that it would load too much fuel to one side of the cylinder. See photo below. Since the nozzle sits at an angle in the head the holes are staggered differently as you move around the circumference of the nozzle. The extra holes are staggered incorrectly which also negatively affects the spray pattern. It was recommended that I not put these nozzles in my car. They flowed 164.286%, 157.143%, 207.143%, and 164.286% over stock for a set average of 173.214% over stock.
Bosio race520 7-hole pictured below:
Another piece of interesting information was that the while the Bosch and Chinese nozzles were clean inside about 40% of the Bosio nozzles had to be cleaned before they could be properly evaluated. They suggested this was due to the way in which they were packaged. Both the Bosch and Chinese nozzles came sealed in individual plastic tubes. I would also like to point out to date I have never installed or ran any Bosio nozzle in my car. Iíve driven plenty of cars with them but have never run a set myself. I want to be clear that all of the data I have is from the testing which was not done from a vehicle.
After getting all the results back I noticed 2 things. The first is that all of the nozzles except the OEM Bosch units werenít matched well for consistency within a given set. Some were better than others but none were close to the OEM Bosch. I then decided to try and create some nozzles of my own. I had 3 choices for a starting point and I looked into what I could buy them for near dealer pricing. From least to most expensive they were 1) Chinese nozzles at approx $15 each, Bosio nozzles at approx $30 each, and Bosch nozzles at approx $60 each. I then have processing fees to cover the EDM and Micro Extrude Hone work which for the most part price me out of the current market. I was told the best nozzle to start with was the Bosch as it had a slightly better surface finish and they felt the seat area was also slightly better.
Next I purchased several sets of brand new OEM Bosch nozzles from a Bosch dealer in Wisconsin (was the best price I could find. My dealer here was $80 each). I have since made several sets of varying sizes which have been put into several peopleís cars, some of which are club members. So far we have had great results. We have been able to hold the flow numbers very tight. The last step is they get extrude honed to remove imperfections, polish the inside of the nozzle, and radius the inside of the holes where the fuel flows. That is what makes the pictures of them looks so nice and shiny on the inside. My nozzles are reworked in the USA and they are done one at a time and each one is flow tested as well as cleaned. Given the price point some mass-produced nozzles are designed to meet I feel there is room for improvement when price is not such a main consideration. I include Bosch copper sealing washers as well as clear plastic tubes so you can submerge your old nozzles in WD-40, biodiesel, etc. Iím not making these nozzles to try and make a fortune. Iím doing it because I think I can make a better product that may appeal to some people. I can also make custom sizes for non-standard applications. Essentially Iím not limited to a pre-set number of configurations.
One of my nozzles pictured below:
Before the testing I had collected information as to where each Bosio nozzle fell with respect to size. I was a little surprised by the PP357 vs. the Sprint 520 as well as the PP502 vs. the PP764. Since these did not come out as I had expected I have decided to post a recap of the Bosioís tested from smallest to largest.
Bosio PP357 ------------ 32.143% over stock
Bosio Sprint520 --------- 37.5% over stock
Bosio PP520 ------------ 52.679% over stock
Bosio PP502 ------------ 68.75% over stock
Bosio PP764 ------------ 84.821% over stock
Bosio Race 520 5-hole ---129.464% over stock
Bosio Race 520 7-hole ---173.214% over stock
As I said during my introduction I wasnít planning on posting any of this information yet. However I am being publically accused of selling, ďcrudely re-worked bossch 706 nozzlesĒ. I also had someone call me and say the same individual is telling people Iím using drill bits to enlarge stock Bosch nozzles. All of this is coming from a vendor who has never touched with his own hands or seen with his own eyes a set of Bosch nozzles Iíve had reworked. Itís after these comments that I decided to write this thread.
Iíve been around forums for years and especially from having owned one I know the politics run deep; much deeper than most people ever know. One is forced to learn the hard way whom you really can and cannot trust. I for one donít appreciate my efforts being belittled as I'm sure none of you do either. If you donít like what Iím doing youíre entitled to that opinion but donít be childish and make up lies in an attempt to discredit me.
So for the record Iím not telling all of you to go buy my nozzles. I havenít even advertised them on the club, in my signature, etc. Iím just laying out everything Iíve done and learned and hopefully some of you will learn something from it too.
I forgot to add that I have tested Bosch PD100 and PD150 nozzles as well as Bosio Race783 PD nozzles. It wasn't the focus of this thread but I have done the testing on them. To summarize the results briefly:
A PD150 nozzle flows 23.077% more than a PD100 nozzle. A Bosio Race783 flows 178.846% more than a PD100 nozzle.
The set of PD100 and PD150 nozzles I tested all flowed exactly the same within their respective sets. The Race783's showed no internal manufacturing defects from the EDM process. The spray pattern was good as was the surface finish. They flowed 184.615%, 184.615%, 176.923%, and 169.231% over a stock PD100 nozzle for a set average of 178.846% over a stock PD100 nozzle.